Muffin pan



FIG. 1 is a perspective view of the muffin pan;

FIG. 2 is a left side elevational view of the muffin pan, the right side elevational view being a mirror image thereof;

FIG. 3 is a front elevational view of the muffin pan, the rear elevational view being a mirror image thereof;

FIG. 4 is a top plan view of the muffin pan; and,

FIG. 5 is a bottom plan view of the muffin pan. 

The ornamental design for a muffin pan, as shown and described. 